2015 Coal First Aid Statements No. 4 Taken from the 2015 National Coal First Aid Contest Rules Progress Indicator: Question 7 of 20 7.  When demonstrating proficiency in gas testing while working a MNM mine rescue contest field problem, methane readings are considered to be correct if within plus or minus ________________________: Choices: 0.2% by volume of the actual value present. 2% of the actual LEL value present. 2% by volume of the actual value present. 0.2% of the actual LEL value present.